Membrane filter device for filtering oily water

Abstract

A membrane filter device according to the present invention comprises: at least one filter housing; at least one membrane filter disposed within the at least one filter housing; at least one lower cap attached to the lower end of the at least one filter housing through a first housing coupling member and including an inlet for raw water; at least one upper cap attached to the upper end of the at least one filter housing through a second housing coupling member and including a first outlet and a second outlet; and an air supply port for supplying air to an inner space of the upper cap, wherein first filtered water obtained by filtering the raw water, injected through an injection port, through the at least one membrane filter can be discharged through a first discharge port, and second filtered water and condensed water generated as backwashing is performed on the at least one membrane filter via the water injected through the first discharge port can be discharged through a second discharge port. Here, the water injected through the first outlet comes into contact with the air as the backwashing is performed.

Description

Membrane filter device for filtration of meteoric water

[0001] The present invention relates to a membrane filter for filtering oily water, and more particularly, to the structure and function of a membrane filter device for filtering oily water for producing treated water suitable for oily water discharge standards.

[0002]

[0003] A membrane is a filter medium that performs a filtration function by selectively allowing only certain components within input seawater, fresh water, or / and oily water to pass through. Membranes can not only filter dissolved substances in liquids, but also separate mixed gases.

[0004]

[0005] The present invention has been devised to solve the above-described problems, and the purpose of the present invention is to provide a structure and function of a membrane filter device for filtering oily water to produce treated water suitable for oily water discharge standards.

[0006] The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0007]

[0008] According to one embodiment of the present invention, a membrane filter device comprises: one or more filter housings; one or more membrane filters disposed within the one or more filter housings; one or more lower caps attached to the lower end of each of the one or more filter housings via a first housing coupling member and including an inlet for raw water; one or more upper caps attached to the upper end of each of the one or more filter housings via a second housing coupling member and including a first outlet and a second outlet; and an air supply port for supplying air to an internal space of the upper cap, wherein the first filtered water filtered through the one or more membrane filters by the raw water injected through the inlet is discharged through the first outlet, and the second filtered water and condensed water generated by performing backwashing on the one or more membrane filters through the water injected through the first outlet can be discharged through the second outlet. Additionally, as the above reverse washing is performed, the water injected through the first outlet comes into contact with the air.

[0009] And, the pore size of the membrane may be 0.05 to 0.25 μm.

[0010] And, the condensate generated as the raw water injected through the inlet is filtered through the one or more membrane filters and the condensate generated as the backwashing is performed can be stored in i) a first storage space included in the one or more upper caps or a second storage space arranged in at least one of the one or more filter housings or ii) an external storage container connected to the membrane filter device.

[0011] And, the first discharge port and the second discharge port may be arranged in a side area of ​​the one or more upper caps.

[0012] And, each of the one or more filter housings may include a stainless steel material.

[0013] And, the one or more lower caps and the one or more filter housings can be detached and attached by the first housing coupling member, and the one or more upper caps and the one or more filter housings can be detached and attached by the second housing coupling member.

[0014] And, the one or more membrane filters can be detachably attached to the one or more filter housings.

[0015] And, the inner space of the upper cap and the upper space of the filter housing can be defined as one space.

[0016] And, the particle size of the emulsion included in at least one of the second filtered water and the condensed water may be 0.2 to 8.0 μm.

[0017] And, the one or more membrane filters can be cleaned with an oil-based cleaning solution composition, wherein the oil-based cleaning solution composition can be any of the embodiments of the present disclosure.

[0018] And, the concentration of oil contained in at least one of the second filtered water and the condensed water may be 0 ppm.

[0019] And, the pore size of the membrane may be 0.10 to 0.20 μm.

[0020]

[0021] By various embodiments of the present invention, the structure and function of a membrane filter device for filtering oily water for producing treated water suitable for the discharge standards of oily water can be provided.

[0022] In addition, according to various embodiments of the present invention, the membrane filter is detachably connected to the housing, making filter replacement easy and allowing it to be easily attached and detached as needed during the work process.

[0023] In addition, according to various embodiments of the present invention, oil component contaminants can be more efficiently filtered through the upper cap discharge port of the membrane filter.

[0024] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0025]

[0026] FIG. 1 is a drawing for explaining the structure of a unit membrane filter element according to one embodiment of the present invention.

[0027] FIG. 2 is a drawing for explaining the structure of an upper cap and a lower cap according to one embodiment of the present invention.

[0028] FIG. 3 is a drawing for explaining the structure of a membrane filter device in which a plurality of membrane filter elements are combined according to one embodiment of the present invention.

[0029] FIG. 4a and FIG. 4b illustrate a process in which filtered water and condensed water are discharged through a membrane filter device according to one embodiment of the present invention.

[0030] FIG. 5 is a drawing for explaining a method for performing a filling process according to one embodiment of the present invention.

[0031] FIG. 6 is a drawing for explaining a method of performing a filtration process according to one embodiment of the present invention.

[0032] FIG. 7 is a drawing for explaining a method of performing back-flushing according to one embodiment of the present invention.

[0033] FIG. 8 is a drawing for explaining a method for performing a drain process according to one embodiment of the present invention.

[0034] FIG. 9 is a drawing for explaining a chemical cleaning process according to one embodiment of the present invention.

[0035] FIG. 10 is a drawing for explaining a chemical circulation process according to one embodiment of the present invention.

[0036] FIG. 11 is a drawing for explaining a chemical discharge process according to one embodiment of the present invention.

[0037] FIG. 12 is a drawing for explaining a rinsing process according to one embodiment of the present invention.

[0038] FIG. 13 is a drawing for explaining a drain process according to one embodiment of the present invention.

[0039]

[0040] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined solely by the scope of the claims.

[0041] The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms, unless specifically stated otherwise. As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components in addition to the components mentioned.

[0042] Throughout the specification, the same reference numerals refer to the same elements, and the term "and / or" includes each and every combination of the elements mentioned. Although terms such as "first," "second," etc. are used to describe various elements, these elements are not limited by these terms. These terms are used only to distinguish one element from another. Therefore, it should be understood that a first element mentioned below may also be a second element within the technical scope of the present invention.

[0043] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those skilled in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0044] Spatially relative terms such as "below," "beneath," "lower," "above," and "upper" may be used to easily describe the relationship of one component to another, as illustrated in the drawings. Spatially relative terms should be understood to include different orientations of components during use or operation in addition to the orientations illustrated in the drawings.

[0045] For example, if a component depicted in a drawing is flipped, a component described as "below" or "beneath" another component may be positioned "above" the other component. Thus, the exemplary term "below" may encompass both the above and below orientations. Components may also be oriented in other directions, and thus spatially relative terms may be interpreted based on their orientation.

[0046] The numerical range indicated by the term "to" in this specification refers to a numerical range that includes the values ​​described before and after the term as the lower limit and the upper limit, respectively. If a plurality of numerical values ​​are invented as the upper limit and the lower limit of an arbitrary numerical range, the numerical range invented in this specification can be understood as an arbitrary numerical range that includes any one of the plurality of lower limit values ​​and any one of the plurality of upper limit values ​​as the lower limit and the upper limit, respectively.

[0047]

[0048] FIG. 1 is a drawing for explaining the structure of a unit membrane filter element according to one embodiment of the present invention.

[0049] A membrane filter device may refer to a device that combines one or more unit membrane filter elements. A unit membrane filter element refers to a structure in which other components are attached to a unit filter housing (110). For the convenience of describing the present invention, FIG. 1 assumes that there is one unit membrane filter element in the membrane filter device.

[0050] A membrane filter device (100) according to one embodiment of the present invention may include a filter housing (110), one or more membrane filters (120-1, 120-2), an upper cap (130), and a lower cap (140).

[0051] The filter housing (110) may include a stainless steel material. If the filter housing (110) is composed / manufactured of a stainless steel material, the weight of the filter housing (110) can be reduced. In addition, bending or damage to the filter housing due to fire or heat within the ship can be prevented. If the filter housing is made of carbon steel, the thickness must be increased to account for corrosion margin, which may cause difficulties in installation and disassembly due to the increased weight of the filter housing.

[0052] One or more membrane filters (120-1, 120-2) may be arranged within the filter housing (110). For example, one or more membrane filters (120-1, 120-2) may be detachably coupled within the filter housing.

[0053] In the past, in the case of a method of fixing a membrane filter to the top of a filter housing, there was a problem in that contaminants in the membrane filter were concentrated in the top of the filter housing, and even if an exhaust port was provided around the concentrated area (e.g., on the side), the contaminants were not effectively discharged due to the cohesiveness of the contaminants.

[0054] According to one aspect of the present invention, one or more membrane filters are detachably attached to the filter housing, thereby further increasing the efficiency of pollutant discharge.

[0055] FIG. 1 illustrates a case where two membrane filters (120-1, 120-2) are provided / attached inside a filtering housing (110), but is not limited thereto. One or more membrane filters may be provided / attached inside the filtering housing (110).

[0056] When the contamination of the membrane filter (120-1, 120-2) is serious or the differential pressure within the membrane filter (120-1, 120-2) increases, the membrane filter (120-1, 120-2) can be easily removed from the filter housing (110) and replaced.

[0057] According to one embodiment of the present invention, the pore size of the membrane in the membrane filter (120-1, 120-2) may be 0.05 to 0.25 μm, 0.07 to 0.24 μm, 0.08 to 0.20 μm, or 0.10 to 0.20 μm. When the pore size of the membrane satisfies the numerical range, oil particles contained in the raw water can be effectively filtered in the internal pores of the membrane filter.

[0058] According to another embodiment of the present invention, the membrane filter (120-1, 120-2) may include a pressurized hollow fiber. According to one aspect of the present invention, by using a hollow fiber with a relatively large surface area as the membrane filter, contaminants, oil, etc. contained in raw water can be more effectively filtered.

[0059]

[0060] *A lower cap (130) may be attached to the lower portion (or lower region) of the filter housing (110) via a first housing coupling member. The lower cap (130) may include an inlet (140) into which raw water is injected and an air supply port (135).

[0061] The air supply port (135) according to the present invention can supply air to the water injected through the first outlet (160) as reverse washing is performed. In some examples, the air supply port (135) can be disposed at the lower end of the lower cap (130), and specifically, can be disposed at a position opposite the injection port (140). According to some embodiments of the present invention, since the air supply port (135) is disposed at the lower end of the lower cap (130), the area where the water injected through the first outlet comes into contact with the air during reverse washing becomes wider per unit time, so that the cyclone can be generated more strongly, and thus the reverse washing efficiency can be further improved. If the air supply port is provided at the upper end of the filter housing (110), the cyclone may not be generated sufficiently strongly, which may cause a problem in that the reverse washing efficiency cannot be sufficiently improved.

[0062] According to another embodiment of the present invention, the air supply port (135) may supply air bubbles in addition to the air. Here, air bubbles may refer to air surrounded by a liquid (e.g., water), unlike air composed of pure gas. In other words, the air supply port (135) may serve to supply both air and air bubbles.

[0063] According to another embodiment of the present invention, the membrane filter device may further include an air bubble supply unit (not shown) connected to the air supply port (135). Unlike the above-described embodiment, an air bubble supply unit may be additionally provided to supply air bubbles to the air supply port (135).

[0064] According to another embodiment of the present invention, by additionally including air bubbles in addition to the air, the reverse cleaning efficiency can be further increased. For example, the volume ratio of the air to the air bubbles can be 9:1 to 5:5, or 8:2 to 7:3.

[0065] Here, the raw water may include one or a mixture of two or more selected from the group consisting of sea water, fresh water, and oily water. That is, the user may inject the raw water into the inlet (140) to filter various contaminants contained in the raw water through the membrane filter device (100).

[0066] An upper cap (150) may be attached to the top (or upper region) of the filter housing (110) via a second housing coupling member. The upper cap (150) may include a first discharge port (160), a second discharge port (170), and / or a storage space (e.g., a specific space of the upper cap (150)) (180) for storing condensate.

[0067] According to another embodiment of the present invention, the filtered water is discharged through the first discharge port (160) and the sludge is accumulated in the upper cap (150) which functions as a wastewater tank, and when back-flushing is performed, the discharged water introduced through the first discharge port (160) is combined with the air supplied through the air supply port (135) to create a strong cyclone and is discharged through the second discharge port (170) located in the upper cap (150), thereby preventing the membrane from being contaminated and continuously maintaining its performance. On the other hand, in the existing method, after the membrane filters and passes the dissolved substances dissolved in the liquid, the remaining residue continuously accumulates in the upper part of the filtering housing (110) connected to the lower part of the upper cap, contaminating the membrane and lowering its performance, which may gradually cause the membrane function to be lost. In addition, when back-flushing, the discharged water introduced through the first discharge port (160) is combined with the air supplied through the air supply port (135) and discharged through the second discharge port on the side of the filtering housing (110), but it is difficult to remove the residue accumulated in the upper part of the filtering housing (100). The present invention is equipped with an upper cap (150) that functions as a sewage tank, and sufficiently treats the residue through back-flushing performed about every 20 minutes, thereby maintaining a state in which the membrane can continuously treat oily water at an operating pressure of 3 BAR or more. Considering that the membrane is composed of microscopic pores, the existing method may have limitations in operating pressure and may cause continuous degradation of membrane performance during operation.

[0068] Specifically, the internal space of the upper cap (150) and the upper space of the filter housing (110) can be defined as one space. That is, the internal space of the upper cap (150) and the upper space of the filter housing (110) can be directly connected. Air or a separate substance on the upper space of the filter housing (110) can move to the internal space of the upper cap (150).

[0069] Accordingly, condensate that has passed through one or more membrane filters (120-1, 120-2) within the filter housing (110) can be accommodated in a storage space (180) for storing condensate.

[0070] Additionally or alternatively, the upper cap (150) may include a first storage member for storing separate condensate, and the filtering housing (110) may include a second storage member for storing separate condensate.

[0071] As shown in FIG. 1, for example, the first discharge port (160) and the second discharge port (170) may be arranged in the side area of ​​the upper cap (180).

[0072] The lower cap (130) and the filter housing (110) can be detached by the first housing coupling member. And, the upper cap (150) and the filter housing (110) can be detached by the second housing coupling member.

[0073] That is, the filtering housing (110) can be easily detached from the lower cap (130) and the lower cap (150). Accordingly, a technical effect can be achieved in which the filtering housing (110) can be easily detached and replaced even in narrow areas and at limited heights within a ship.

[0074] The process of discharging various types of filtered water and condensed water through the first discharge port (160), the second discharge port (170), and the storage member (180) will be described in detail with reference to FIGS. 4a and 4b.

[0075] For example, the length from the central region of the second discharge port (170) to the inlet port (140) may be 1816 mm, the length from the top of the upper cap (150) to the inlet port (140) may be 1879 mm, and the length from the top end of the first discharge port (160) to the inlet port (140) may be 1886 mm.

[0076] However, this is only one example, and the length and width between the components of the membrane filter device (100) may vary.

[0077]

[0078] FIG. 2 is a drawing for explaining the structure of an upper cap and a lower cap according to one embodiment of the present invention.

[0079] As described with reference to FIG. 1, a first outlet and a second outlet can be coupled / attached to the upper cap, and an inlet can be coupled / attached to the lower cap.

[0080] As shown in Fig. 2(a), a first connecting member (180) for connecting / attaching each of the first outlet and the second outlet to an external pipe may be configured, and a second connecting member (190) for connecting / attaching the inlet to the external pipe may be configured within the membrane filter device.

[0081] Fig. 2(b) illustrates the structure of the first connecting member (180) for connecting / attaching each of the first outlet and the second outlet to an external pipe.

[0082] A gasket may be connected / attached to the first outlet and / or the second outlet. The first outlet and / or the second outlet may be connected to the first connecting member (180) through the gasket. In addition, the filtered water or / and condensed water discharged through the first outlet and / or the second outlet may be discharged through a pipe. The numerical values ​​shown in (b) of Fig. 2 are merely examples and may be determined to be different values.

[0083] FIG. 2(c) illustrates the structure of a second connecting member (190) for connecting / attaching each inlet (i.e., membrane module) to an external pipe.

[0084] A gasket may be connected / attached to the inlet. The inlet and the second connecting member (190) may be connected via the gasket. Furthermore, raw water injected through the pipe may be delivered into the membrane filter device through the inlet. The numerical values ​​shown in (c) of Fig. 2 are merely exemplary and may be determined to be different values.

[0085] For example, the distance between the gasket and the first connecting member (180) may be 1.0 to 2.0 mm, 1.2 to 1.8 mm, 1.5 to 1.7 mm, or 1.6 mm. Additionally, the distance between the gasket and the second connecting member (190) may be the same as or different from the distance between the gasket and the first connecting member (180).

[0086]

[0087] FIG. 3 is a drawing illustrating the structure of a membrane filter device comprising a plurality of membrane filter elements, according to one embodiment of the present invention. Although FIG. 3 illustrates a membrane filter device comprising two membrane filter elements, the number of membrane filter elements may be determined to various values.

[0088] As illustrated in FIG. 3, the membrane filter device (1000) may be composed of a first membrane filter element (100) and a second membrane filter element (200). The structure of each of the first membrane filter element (100) and the second membrane filter element (200) may be configured as in FIG. 1, and the first membrane filter element (100) and the second membrane filter element (200) may be connected to each other to configure the membrane filter device (1000).

[0089] One or more pipes may be connected to the first outlet, the second outlet, and the inlet included in each of the first membrane filter element (100) and the second membrane filter element (200).

[0090]

[0091] FIGS. 4A and 4B are diagrams illustrating a process of discharging filtered water and condensed water through a membrane filter device according to one embodiment of the present invention. For convenience of explanation of the present invention, FIGS. 4A and 4B assume that the membrane filter device has a single membrane filter element.

[0092] Figure 4a is a drawing for explaining a filtering procedure using a membrane filter device.

[0093] Based on the raw water being injected through the inlet, the raw water can be filtered of various oil residues and floating substances by passing through one or more membrane filters attached within the filtering housing (110). The first filtered water from which various oil residues and floating substances have been filtered can be discharged through the first discharge port (160).

[0094] At this time, the valve of the second outlet may be locked, and the condensate containing various oil residues and floating substances may be stored in the storage member / storage space included in the upper cap or / and the filtering housing (110).

[0095] Additionally or alternatively, the condensate containing various oil residues and suspended solids may be stored in a separate external storage container connected to the membrane filter device.

[0096] Figure 4b is a drawing for explaining a back-flushing procedure using a membrane filter device.

[0097] Based on the fresh water being injected through the first outlet (160), a backwashing procedure can be performed to remove contaminants attached to the surface of one or more membrane filters included in the filtering housing (110). The second filtered water and the condensed water generated as the backwashing is performed can be discharged through the second outlet (170). The particle size of the emulsion included in at least one of the second filtered water and the condensed water can be 0.2 to 0.8 μm. In addition, the concentration of oil included in at least one of the second filtered water and the condensed water can be 0 ppm.

[0098] At this time, the condensate may include not only the condensate generated as the backwash is performed, but also the condensate stored within the storage member / space.

[0099] As described above, the life of the membrane filter can be increased as the first discharge port (160) and the second discharge port (170) are located at the upper part of the filtering housing (110).

[0100] Specifically, by arranging the second discharge port (170) in the upper cap and connecting the upper space of the upper cap and the filtering housing (110) into one space, the space inside the upper cap (i.e., the space inside the storage member) can be utilized as a space for capturing oil components that contaminate the membrane filter.

[0101] Oil components, etc. existing in the space inside the upper cap (i.e., the space inside the storage member) can be discharged through the second discharge port (150) when performing a reverse cleaning procedure, thereby minimizing contamination of the membrane filter and increasing the lifespan of the membrane filter.

[0102] In another embodiment of the present invention, the filtering operation illustrated in FIG. 4A and the backwashing operation illustrated in FIG. 4B may be performed simultaneously. Specifically, the backwashing procedure may be performed using water input through the first outlet while raw water input through the inlet passes through one or more membrane filters.

[0103] According to another embodiment of the present invention, a ship exhaust gas treatment device including the membrane filter device can be provided. Therefore, the subject matter of the present invention can be changed from a membrane filter device to a ship exhaust gas treatment device. According to one aspect of the present invention, when the membrane filter device is applied to a ship exhaust gas treatment device, oil particles can be effectively filtered from raw water, thereby discharging treated water that meets discharge standards.

[0104] The membrane filtration process refers to a process that removes oil sludge and / or suspended solids from raw water (or treatment water) produced in a water treatment module (or unit) through a membrane filter and / or hollow fiber membrane filter, thereby producing filtered water that meets ship discharge regulatory requirements. To efficiently perform the membrane filtration process, continuous cleaning of the membrane filter device and related piping is required.

[0105] Here, the raw water may include one or a mixture of two or more selected from the group consisting of sea water, fresh water, and oily water.

[0106] A membrane filtration process according to one embodiment of the present invention may consist of i) normal operation of a membrane filtration facility and ii) chemical cleaning (Cleaning in place, CIP) of cleaning the membrane filter with a chemical agent.

[0107] Normal operation may consist of a water supply process, a filtration process, a backwash process, and a drainage process. The backwash process may be performed after the filtration process has been stopped and before restarting. Chemical cleaning may consist of a chemical injection process into the cleaning tank, a chemical circulation process, a discharge process, a rinsing process, and a drainage process.

[0108] When a membrane filter device is newly installed as a filtration process facility, a normal operation cycle (i.e., water supply process, filtration process, backwash process, and drainage process) may be performed first to ensure the stability of normal operation.

[0109] The operating time for each process can be adjusted based on the default setting and / or design conditions. Depending on the quality of the raw water supplied from the water treatment module and other conditions, the operating time for each process may change from the default setting.

[0110] Below, the process of constructing a membrane filtration system will be described in detail with reference to the drawings.

[0111]

[0112] FIG. 5 is a drawing for explaining a method for performing a filling process according to one embodiment of the present invention.

[0113] The water supply process means a process of filling one or more membrane filter devices (100, 200) with raw water through a water supply module (i.e., water treatment unit (WTU)) (10).

[0114] Specifically, the WTU raw water supply valve connected to the WTU (10) can be opened while the back-flushing pump (32) is open. That is, the WTU (10) opens the valve connected to the tank (13) containing the raw water and operates the water supply pump (15) connected to the tank (13), thereby supplying raw water to one or more membrane filter devices (100, 200) included in the pipe and filtering module (20) connected to the WTU (10). At this time, the WTU (10) can operate the water supply pump (15) for a preset time (e.g., 20 seconds).

[0115] In the water supply process, the valve at the outlet of the membrane filter device and other valves may all be closed.

[0116]

[0117] FIG. 6 is a drawing for explaining a method of performing a filtration process according to one embodiment of the present invention.

[0118] The filtration process refers to a process of removing oil sludge and suspended solids in the raw water by passing the raw water supplied from the WTU (10) through one or more membrane filter devices (100, 200).

[0119] As described above, the WTU (10) can supply raw water to one or more membrane filter devices (100, 200) through a pipe (22) connected to the WTU (10) by opening a valve connected to a tank (13) containing raw water and operating a water supply pump (15) connected to the tank (13).

[0120] Specifically, the filtering module (20) can input raw water supplied from the WTU (10) into one or more membrane filter devices (100, 200) to obtain filtered water and first condensate. The particle size of the emulsion included in the first condensate may be 0.2 to 8.0 μm. The device can discharge the filtered water through a pipe (or, pipe) (24) connected to the first outlet of one or more membrane filter devices (100, 200).

[0121] At this time, the upper cap located on the top of one or more membrane filter devices may include a storage space for capturing the first condensate. The first condensate obtained by one or more membrane filter devices (100, 200) may be stored in the storage space.

[0122]

[0123] FIG. 7 is a drawing for explaining a method of performing back-flushing according to one embodiment of the present invention.

[0124] The reverse washing process (or / and air bubble washing process) is a process for removing contaminants attached to the membrane filter surface and pores by supplying fresh water (i.e., reverse washing water) from the secondary membrane to the primary membrane side during the membrane filtration process.

[0125] The reverse cleaning module (30) can supply reverse cleaning water to the filtering module (20) by operating the reverse cleaning pump (32). At this time, the reverse cleaning module (30) can supply bubbles to the reverse cleaning water through the reverse cleaning pump (32) and / or a pipe connected thereto.

[0126] In order to efficiently reverse-clean the membrane filter, the reverse-cleaning pump (320) can supply reverse-cleaning water with sufficient flow rate to the filtering module (20). The flow rate of the reverse-cleaning water supplied to the filtering module (20) by the reverse-cleaning module (30) is 3 bar * 3 m 3 / h to 6 bar * 5m3 It could be / h.

[0127] That is, based on the second condensate being obtained by inputting the reverse-washing water supplied from the reverse-washing module (30) into the first discharge port, one or more first condensates and second condensates can be discharged through a pipe (32) connected to the second discharge port of the membrane filter device (100, 200). The first condensates and second condensates discharged through the pipe (32) connected to the second discharge port can be stored in an EGR drain tank.

[0128] As an example of the present invention, while raw water is supplied from the water treatment module (10) to the filtering module (20), backwash water is supplied from the backwash module (30) to the filtering module (20), and while the filtered water is discharged through the first outlet, the first condensate and the second condensate can be discharged through the second outlet. Here, the particle size of the emulsion included in the second condensate can be 0.2 to 8.0 μm. That is, the filtration process and the backwash process can be performed simultaneously.

[0129]

[0130] FIG. 8 is a drawing for explaining a method for performing a drain process according to one embodiment of the present invention.

[0131] When the reverse cleaning process described with reference to FIG. 8 is completed, the filtering module (20) can drain the first condensate and the second condensate by opening the discharge valve connected to the vent and the second discharge port.

[0132]

[0133] FIG. 9 is a drawing for explaining a chemical cleaning process according to one embodiment of the present invention.

[0134] The chemical cleaning in place (CIP) process refers to a process of cleaning the membrane filter with a chemical component when the differential pressure approaches the operating limit differential pressure (e.g., 1.0 bar, 100 kPa) even after reverse cleaning due to long-term operation of the membrane filter device or changes in the quality of WTU treated water.

[0135] The chemical cleaning cycle may be increased or decreased depending on the condition of the membrane filter, the water quality of the WTU treated water, and other factors, as the differential pressure rise trend varies. However, the differential pressure must not exceed the operating limit, and an increase in the chemical cleaning cycle may indicate membrane damage.

[0136] A system according to the present invention may include a control device that controls a WTU (10), a filtering module (20), a backwashing module (30), and a CIP module (40). If it is determined that the cycle in which the CIP module performs chemical cleaning is less than a critical period, the control device may transmit a message requesting replacement of a membrane filter in one or more membrane filter devices (100, 200) to a terminal device used by a system administrator.

[0137] As an example of the present invention, after the first condensate (i.e., condensate generated through the filtration process) and the second condensate (i.e., condensate generated through the backwash process) are discharged through the second outlet of the membrane filter device, the CIP module (40) can perform chemical cleaning on the one or more membrane filter devices based on the pressure within the one or more membrane filter devices (100, 200) being within a critical range.

[0138] Additionally or alternatively, the CIP module (40) can perform chemical cleaning on one or more membrane filter devices (100, 200) at predefined intervals. Here, the oily water cleaning solution composition for membrane filters used for chemical cleaning comprises a chemical cleaning solution and water.

[0139] The oil-based cleaning solution composition for a membrane filter according to the present invention comprises a chemical cleaning solution and water.

[0140] The chemical cleaning solution according to the present invention comprises a wetting agent, a stabilizer, a surfactant, an emulsifying film remover, and purified water.

[0141] humectant

[0142] The wetting agent according to the present invention can not only realize high cleaning power and emulsifying power of the cleaning liquid composition, but also contribute to the good mixing of contaminants attached to the surface of the membrane filter into water. In addition, the wetting agent according to another aspect of the present invention can effectively prevent excessive foaming within the oily water cleaning liquid composition for the membrane filter.

[0143] The content of the wetting agent according to the present invention may be 6 to 14 wt%, 7 to 13 wt%, 8 to 12 wt%, 9 to 11 wt%, or 10 to 11 wt% based on the total weight of the chemical cleaning solution. Specifically, if the content of the wetting agent is less than the above numerical range, contaminants attached to the surface of the membrane filter may not mix well with water, so that the chemical cleaning function may not be effectively performed, and if it exceeds the above numerical range, the flowability of the cleaning solution composition may be reduced, so that the cleaning efficiency may be reduced.

[0144] The wetting agent according to the present invention may include a sulfonate. Specifically, the sulfonate not only exhibits higher cleaning and emulsifying power than other types of wetting agents, but also contributes to better mixing of contaminants attached to the surface of a membrane filter with water.

[0145] For example, the sulfonate may be one or a mixture of two or more selected from the group consisting of sodium xylenesulphonate, sodium dodecylbenzenesulfonate, and sodium perfluorooctane sulfonate. However, the technical idea of ​​the present invention is not limited thereto, and any sulfonate that functions as a wetting agent may be applied.

[0146] stabilizer

[0147] The stabilizer according to the present invention can contribute to the well-dispersion of lipophilic contaminants attached to the membrane filter in water. Accordingly, the stabilizer effectively prevents the lipophilic contaminants from separating by ensuring their well-dispersion in water, thereby achieving a stabilizing effect in the cleaning solution composition.

[0148] The stabilizer according to the present invention may be present in an amount of 1 to 9 wt%, 2 to 8 wt%, 3 to 7 wt%, 4 to 6 wt%, or 5 to 6 wt% based on the total weight of the chemical cleaning solution. Specifically, if the content of the stabilizer is less than the above numerical range, lipophilic contaminants may not be well dispersed in water, resulting in problems of separation from water. If the content exceeds the above numerical range, the flowability of the cleaning solution composition may be reduced, resulting in reduced cleaning efficiency.

[0149] For example, the stabilizer may be one or a mixture of two or more selected from the group consisting of sodium tripolyphosphate, sodium hexametaphosphate, sodium polymetaphosphate, disodium pyrophosphate, and sodium carboxymethylcellulose.

[0150] surfactant

[0151] The surfactant according to the present invention can relax the interface between lipophilic contaminants attached to a membrane filter and water. Consequently, the surface tension at the interface between the lipophilic contaminants and water is weakened, allowing the lipophilic contaminants attached to the membrane filter to be effectively removed.

[0152] The surfactant according to the present invention may include at least one selected from the group consisting of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants, and may specifically include a nonionic surfactant. According to one embodiment of the present invention, by using a nonionic surfactant as the surfactant, not only can an excellent cleaning action be achieved even at low temperatures, but also the effect of reducing foaming in the cleaning liquid composition can be realized.

[0153] For example, the anionic surfactant may include a hydrophilic functional group as a substance that has the property of lowering surface tension by adsorbing anions generated by dissociation in water to the surface of an aqueous solution. Here, the hydrophilic functional group may include at least one of a carboxyl group, a phosphoric acid group, and a sulfonate group. According to one example, the anionic surfactant may be one or a mixture of two or more selected from the group consisting of lauryl ammonium phosphate, cetyl ammonium phosphate, tetradecylammonium phosphate, lauryl ammonium sulfate, cetyl ammonium sulfate, dodecylbenzene ammonium sulfate, ammonium hexadecyl ether sulfate, tridecyl ammonium phosphate, tetradecyl ammonium phosphate, dilauryl ammonium phosphate, dicetyl ammonium phosphate, ditridecyl ammonium phosphate, tetradecyl ammonium sulfate, tridecyl benzene ammonium sulfate, dodecylammonium sulfate, hexadecylammonium sulfate, and lauryl ammonium carboxylate.

[0154] For example, a cationic surfactant is a substance that has the property of lowering surface tension by adsorbing cations formed by dissociation in water onto the surface of an aqueous solution. According to one example, the cationic surfactant may be any one selected from the group consisting of stearalkonium chloride, stearyltrimonium chloride, distearyl-dimonium chloride, and mixtures thereof.

[0155] For example, the amphoteric surfactant may be a compound that can change into an anionic, cationic, or nonionic state in an aqueous solution depending on the pH of the water. According to one example, the amphoteric surfactant is didecyl ethanolamine oxide, dodecyl dimethylamine oxide, tetradecyl dimethylamine oxide, hexadecyl dimethylamine oxide, octadecyl dimethylamine oxide, coco dimethylamine oxide, coco bis(2-hydroxyethyl)amine oxide, dicoco dimethylamine oxide, dicocoethanolamine oxide, cocoylamidopropyl dimethylamine oxide, tallow dimethylamine oxide, tallow diethanolamine oxide, ditallow methylamine oxide, ditallow ethanolamine oxide, di(hydrogenated tallow) methylamine oxide, tallowylamidopropyl dimethylamine oxide, 9-octadecenoyl dimethylamine oxide, N-cocomorpholine N-oxide, coco dimethylbetaine, cocoylamidopropyl dimethyl betaine, lauroylamidopropyl dimethyl betaine, It may be one or a mixture of two or more selected from the group consisting of cocoamphocarboxyglycinate, tallow amphopolycarboxyglycinate, and N-coco-3-amino-butyric acid.

[0156] For example, the nonionic surfactant may be one or a mixture of two or more selected from the group consisting of alkyl polyglucoside, polyoxyethylene polyoxypropylene condensate, polyoxyethylene polyoxybutylene condensate, glycerin-added polyoxyethylene polyoxypropylene condensate, ethylenediamine-added polyoxyethylene polyoxypropylene condensate, polyoxyalkylene alkyl ether, polyoxyalkylene alkyl phenol ether, polyoxyalkylene aryl phenol ether, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene alkyl amine, sorbitan fatty acid ester, alkyl alcohol amine, and aryl alcohol amine.

[0157] The content of the surfactant according to the present invention may be 6 to 14 wt%, 7 to 13 wt%, 8 to 12 wt%, 9 to 11 wt%, or 10 to 11 wt% based on the total weight of the chemical cleaning solution. If the content of the surfactant is less than the above numerical range, the surface tension of the interface between the lipophilic contaminant and water may become less weak, which may cause a problem in that the lipophilic contaminant attached to the membrane filter may not be effectively removed, and if the content exceeds the above numerical range, a problem in that the cleaning efficiency may decrease may occur.

[0158] Emulsion remover

[0159] An emulsified film remover according to one aspect of the present invention can effectively prevent the formation of an emulsified film within a cleaning solution composition by stabilizing various impurities contained in oily water, thereby enhancing cleaning power. An emulsified film remover according to another aspect of the present invention can effectively separate lipophilic contaminants attached to the surface of a membrane filter together with water by increasing the pH of the cleaning solution composition.

[0160] The content of the emulsification film remover according to the present invention may be 0.5 to 1.5 wt%, 0.6 to 1.4 wt%, 0.7 to 1.3 wt%, 0.8 to 1.2 wt%, or 0.9 to 1.1 wt% based on the total weight of the chemical cleaning solution. If the content of the emulsification film remover is less than the above numerical range, the impurities contained in the oily water may excessively increase the emulsification film, resulting in a problem of reduced cleaning power, and if the content exceeds the above numerical range, the cleaning effect may be reduced.

[0161] For example, the emulsifying film remover may be any one selected from the group consisting of sodium metasilicate pentahydrate, sodium metasilicate nonahydrate, and mixtures thereof.

[0162] purified water

[0163] The purified water according to the present invention can serve as a solvent that dissolves various components contained in the chemical cleaning solution and can dilute the substance to be cleaned.

[0164] The content of the purified water according to the present invention may be the remaining content excluding the above-described composition based on the total weight of the chemical cleaning solution.

[0165] For example, the content of the purified water may be 70 to 78 wt%, 71 to 77 wt%, 72 to 76 wt%, 73 to 75 wt%, or 74 to 75 wt% based on the total weight of the chemical cleaning solution. If the content of the purified water is less than the above numerical range, a problem may arise in which various substances included in the chemical cleaning solution are not well dissolved, and if it exceeds the above numerical range, a problem may arise in which the cleaning power for lipophilic contaminants attached to the surface of the membrane filter is reduced.

[0166] Detergent composition

[0167] According to another embodiment of the present invention, the volume ratio of the chemical cleaning solution and the water may be 1:9 to 2:8. When the volume ratio of the chemical cleaning solution and the water satisfies the numerical range, the chemical cleaning solution is effectively dispersed in the water, thereby realizing an excellent cleaning effect.

[0168] According to a preferred embodiment of the present invention, the water mixed with the chemical cleaning solution may be substituted with an ester compound having 6 to 8 carbon atoms and a halogen atom at the terminal. According to a preferred embodiment of the present invention, by mixing the chemical cleaning solution with the ester compound having 6 to 8 carbon atoms and a halogen atom at the terminal, a synergistic effect of further lowering the differential pressure of the membrane filter may be exhibited. For example, the ester compound having 6 to 8 carbon atoms and a halogen atom at the terminal may be 6-bromohexyl acetate.

[0169]

[0170] FIG. 10 is a drawing for explaining a chemical circulation process according to one embodiment of the present invention.

[0171] Chemical circulation process refers to the process of circulating a chemical cleaning solution (i.e., a mixture of fresh water and chemicals) through a membrane filter.

[0172] The CIP circulation valve and the chemical cleaning inlet valve can be opened. The CIP module (40) can operate the chemical cleaning solution supply pump (44) to inject the chemical cleaning solution into the filtering module (20). The membrane filter can be cleaned by the chemical cleaning solution for a certain period of time (e.g., 40 minutes).

[0173] For example, if it is determined that foam has been generated inside the CIP tank (43), the CIP module (40) can add a predetermined antifoaming agent inside the CIP tank (43).

[0174]

[0175] FIG. 11 is a drawing for explaining a chemical discharge process according to one embodiment of the present invention.

[0176] When the chemical recirculation process is completed, the chemical cleaning solution can be returned to the chemical cleaning solution tank (43) for reuse. If the contamination level of the chemical cleaning solution exceeds a predefined value and reuse is difficult, the CIP module can operate the chemical cleaning solution discharge valve to send the chemical cleaning solution to the chemical waste tank (45).

[0177]

[0178] FIG. 12 is a drawing for explaining a rinsing process according to one embodiment of the present invention.

[0179] The rinsing process refers to a process of discharging contaminants and chemical cleaning agents separated from the membrane filter surface by chemical cleaning solution circulation and bubbles through the filtering module (20) and the pipe connected thereto, and washing the filtering module (20) and the pipe connected thereto with fresh water.

[0180] A cleaning valve connected to a reverse cleaning module (30) can be opened, and the reverse cleaning module (30) can clean the filtering module (20) and the pipes connected thereto for a certain period of time (e.g., 60 seconds) by injecting fresh water into the filtering module (20). The cleaning water discharged from the rinsing process can be transferred to a chemical waste tank (45).

[0181] Once the rinsing process is complete, the chemical cleaning process is complete, and normal operation can resume. If the membrane filter contamination level or differential pressure remains within a critical range after the CIP process, a manual chemical cleaning process can be performed.

[0182]

[0183] FIG. 13 is a drawing for explaining a drain process according to one embodiment of the present invention.

[0184] Once the chemical discharge process is complete, the vent and drain valves can be opened, allowing chemical residues to be discharged through the discharge port of the membrane filter (e.g., the second discharge port).

[0185] Hereinafter, embodiments of the present invention will be described in detail so that those with ordinary skill in the art can easily implement the present invention. However, this is merely an example, and the scope of the present invention is not limited by the following contents.

[0186] [Manufacturing Preparation Example: Manufacturing of Chemical Detergent]

[0187] A chemical cleaning solution was prepared according to the following Preparation Example 1.

[0188] Preparation for Classification Example 1: Wetting agent 1) 10 wt% stabilizer 2) 5 wt% nonionic surfactant 3) 10 wt% emulsifying film remover 4) 1 wt% purified water 74 wt% 1) Sodium xylenesulphonate 2) Sodium tripolyphosphate 3) Alkyl polyglucoside (a compound with 40 glucose units and 15 carbon atoms in the alkyl group) 4) Sodium metasilicate, pentahydrate

[0189] [Example 1: Preparation of an oily water cleaning solution composition for a membrane filter] An oily water cleaning solution composition was prepared with the contents described in Table 2 below. Meanwhile, the total capacity of the CIP tank was set to 200 L.

[0190] Example 1: Water (dilution) 150.00 L, Chemical cleaning solution of the above Preparation Example 1 16.65 L, Total 166.65 L

[0191] [Experimental Example 1: Results of CIP process using a contaminated filter] As a result of performing the CIP (Chemical in place) process for 41 minutes using the oily water cleaning solution composition according to Example 1, the differential pressure of the membrane filter was measured according to Equation 1 below.

[0192] [Formula 1]

[0193] Pressure difference (△P) = P upstream -P downstream

[0194] In the above equation 1, P upstream is the pressure upstream and P downstream is the pressure downstream.

[0195] In Table 3 below, if the differential pressure is 0.1 bar or less, it may mean that the oily water, impurities, etc. contained in the membrane filter are removed by the oily water cleaning solution composition according to Example 1, and the function of the membrane filter is restored to its original state.

[0196] Differential flow pressure (△P) drawing Note: 3.04 m before CIP test 3 / h1.77barSee also 2.1 hour of raw water circulation status. CIP test after 30 minutes. 2.44m 3 / h0.05barSee also 3 CIP test 41 minutes later 2.46m 3 / h0.05bar See also 4

[0197] [Experimental Example 2: Differential pressure evaluation according to the type of sodium metasilicate hydrate] A cleaning solution composition was prepared in the same manner as Example 1, but the type of sodium metasilicate hydrate was changed to prepare cleaning solution compositions according to Comparative Examples 1 and 2, respectively.

[0198] The differential pressure of the membrane filter 30 minutes after the CIP test was measured using the same method as in Experimental Example 1 above.

[0199] Example 1Comparative Example 1Comparative Example 2CompositionSodium metasilicate pentahydrate 1 wt%Sodium metasilicate nonahydrate 1 wt%Anhydrous sodium metasilicate 1 wt%Differential pressure (△P) of membrane filter after 30 minutes of CIP test0.05 bar (suitable)0.12 bar (unsuitable)0.17 bar (unsuitable)

[0200] In terms of the differential pressure of the membrane filter according to the type of hydrate in Table 4 above, Example 1, Comparative Examples 1 and 2 were compared. It was confirmed that the differential pressure of the membrane filter of Example 1 containing sodium metasilicate pentahydrate reached an appropriate level compared to Comparative Example 1 containing sodium metasilicate nonahydrate; and Comparative Example 2 containing anhydrous sodium metasilicate.

[0201]

[0202] [Experimental Example 3: Different from Example 1, when the type of diluent is different]

[0203] A cleaning composition was prepared in the same manner as in Example 1, but a dilution solution consisting of 145 L of water and 5 L of Stoddard's solvent was used instead of 150 L of water to prepare a cleaning composition of Example 2.

[0204] Example 1 Example 2 Diluted solution 150 L Water 145 L + Stoddard solvent a) Differential pressure (△P) of membrane filter after 30 minutes of 5LCIP test 0.05 bar (suitable) 0.02 bar (very suitable) a) Stoddard solvent (CAS No. 8052-41-3)

[0205] Referring to Table 5 above, it was confirmed that the effect of further lowering the differential pressure of the membrane filter was achieved by using a diluent composed of a mixture of water and Stoddard solvent. At this time, the Stoddard solvent may include an ester compound having 6 to 8 carbon atoms and a halogen atom at the terminal. The ester compound may be a saturated ester compound that does not include a carbon-carbon multiple bond. More specifically, the Stoddard solvent may be 6-bromohexyl acetate.

[0206] Additionally, it was confirmed through various experiments that the pressure difference of the membrane filter was further reduced when the volume ratio of water to Stoddard solvent was 29:1.

[0207] As described above, the embodiments of the invention have been described with reference to the attached drawings. Those skilled in the art will understand that the invention can be implemented in forms other than the disclosed embodiments without altering the technical spirit or essential features of the invention. The disclosed embodiments are illustrative and should not be construed as limiting.

[0208]

[0209] 100: Membrane filter device 110: Filtering housing

[0210] 120-1, 120-2: Membrane filter 130: Lower cap

[0211] 135: Air supply connection member 140: Inlet

[0212] 150: Top cap 160: First outlet

[0213] 170: Second outlet 180: Storage space

Claims

1. One or more filter housings; One or more membrane filters disposed within said one or more filter housings; At least one lower cap attached to the lower end of each of said at least one filter housing via a first housing coupling member and including an inlet for raw water; At least one upper cap attached to the upper end of each of said at least one filter housing via a second housing coupling member, said upper cap including a first outlet and a second outlet; An air supply port for supplying air to the internal space of the upper cap; and An air bubble supply unit connected to the air supply port and supplying air bubbles to the air supply port; The first filtered water, which is filtered through the one or more membrane filters from the raw water injected through the inlet, is discharged through the first outlet, The second filtered water and condensed water generated by performing reverse washing on the one or more membrane filters through the water injected through the first outlet are discharged through the second outlet, As the above reverse washing is performed, the water injected through the first outlet comes into contact with the air, The one or more membrane filters are cleaned with an oily water cleaning solution composition, The above-mentioned oil-based detergent composition is, chemical detergent, water, and Containing an ester compound having 6 to 8 carbon atoms and a halogen atom at the terminal, The above chemical detergent, 10 wt% sodium xylenesulphonate; 5 wt% sodium tripolyphosphate; 10 wt% alkyl polyglucoside; 1 wt% sodium metasilicate pentahydrate and Contains 74% by weight of purified water, The volume ratio of the water and the ester compound is 29:1, The volume ratio of the air and the air bubble is 9:1 to 5:5, Membrane filter device.

2. In paragraph 1, The pore size of the above membrane is 0.05 to 0.25㎛. Membrane filter device.

3. In paragraph 2, The condensate generated as the raw water injected through the inlet is filtered through the one or more membrane filters and the condensate generated as the backwashing is performed are stored in i) a first storage space included in the one or more upper caps and a second storage member arranged in at least one of the one or more filter housings or ii) an external storage container connected to the membrane filter device. Membrane filter device.

4. In paragraph 3, The first outlet and the second outlet are arranged in a side area of the one or more upper caps, Membrane filter device.

5. In paragraph 4, Each of the one or more filter housings comprises a stainless steel material, Membrane filter device.

6. In paragraph 5, The at least one lower cap and the at least one filter housing are detachably attached to each other by the first housing coupling member, The at least one upper cap and the at least one filter housing are detachably attached to each other by the second housing coupling member. Membrane filter device.

7. In paragraph 6, wherein said one or more membrane filters are detachably attached to said one or more filter housings, Membrane filter device.

8. In paragraph 1, The inner space of the upper cap and the upper space of the filter housing are defined as one space. Membrane filter device.

9. In paragraph 1, The concentration of oil contained in at least one of the second filtrate and condensate is 0 ppm, Membrane filter device.

10. In paragraph 1, The pore size of the above membrane is 0.10 to 0.20㎛. Membrane filter device.

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